<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>计算器</title>
    <link rel="stylesheet" href="./css/index.css"
</head>
<body>
    <div id="app">
        <div class="input-num">
            <button @click="sub">-</button>
            <spna>{{num}}</spna>
            <button @click="add">+</button>
        </div>
        <img src="http://www.itheima.com/images/logo.png" alt=""/>
    </div>
    <!-- 开发环境版本，包含了有帮助的命令行警告 -->
    <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
    <script>
        var app=new Vue({
            el:"#app",
            data:{
                num:1
            },methods:{
                add:function(){
                    if(this.num<10){
                        this.num++;
                    }else{
                        alert("别点啦,最大啦");
                    }
                },sub:function(){
                    if(this.num>0){
                        this.num--;
                    }else{
                        alert("别点啦,最小啦");
                    }
                }
            }
        })
    </script>
</body>
</html>